Cf. Bernard Rackham 'A Dated Staffordshire Mug in the National Museum of Wales, Cardiff', E.C.C. Transactions Vol. 2, no. 8, pp. 145-148 for a discussion of this enamelling, where the author attributes the decoration on this armorial mug to an itinerant Dutch or German decorator working in Staffordshire; also see the mug sold at Christie's King Street on 18 June 1984, lot 38. For a discussion of this early form of coffee-pot see Hugh Tait, 'The Earliest English Ceramic Coffee-Pot', Ars Ceramica, No. 4, p. 50.